Automobile jack



1964 A. .1. BELANGER 3,159,382

AUTOMOBILE JACK Filed May 1963 3 Sheets-Sheet l I INVENTOR. APP/VI? J.EfZA/I/GEE 'AfTd/P/Jfff 1964 A. J. BELANGER 3,

AUTOMOBILE JACK Filed May 31, 1963 3 Sheets-Sheet 2 I NVEN TOR. ARTHURJ. BEAM/65E W 1964 A. J. BELANGER 3,

AUTOMOBILE JACK Filed May 31, 1963 5 Sheets-Sheet 3 fie. M,

INVENTOR AFTHM? 1/. Bi'M/VGEE United States Patent 3,159,382 AUTOMQBEE.iAQK Arthur .l. Belanger, 321 .6 fianford St, fvluskegon, Mich. FiledMay 31, 1963, Ser. No. 286,106 9 Claims. {65. Ha -16195) This inventionrelates to a hoist mechanism, especially a vehicle hoist or jack, andmore particularly to a chainlift hoist.

This application is a continuation-in-part application of my copendingapplication entided Automobile lack, filed June 26, 1962, Serial No.205,278 now abandoned.

Various types of chain hoists have been devised heretofore. Since thechain is a flexible and highly adaptable tension element, it isadvantageous to use. As far as is known, however, none has ever gainedwide acceptance for use as a vehicle jack. Heretofore, it has beendifiicult, if not impossible to achieve a simple, manual drive means forthe chain to enable a large mechanical advantage to be obtained withouta complex winching action. Further, as far as is known, no reallysatisfactory method of controllably reversing movement of the chain hasbeen possible on a small scale for lowering the vehicle on the jack orhoist.

It is therefore an object of this invention to provide a compact, chainhoist mechanism enabling simple, manual operation while also achieving alarge mechanical advantage.

It is another object of this invention to provide a chain hoist enablingsmooth operation as a vehicle jack, thereby providing the jack with theflexible characteristic of a chain without the operating difficultiesand reverse move" ment difficulties experienced heretofore.

It is another object of this invention to provide a rollerchain hoisthaving an easily controlled reverse action in eccentric element.Further, the eccentric is controlled in the amount of binding forcewhich it applies to the roller chain due to a control element operablebetween the eccentric and its mounting bracket.

It is still another object of this invention to provide a chain hoisthaving an easily cor roiled reverse action in a link by link manner bythe use of magnetic actuating means mounted on the handle of the jack.

These and many other objects of this invention will be apparent uponstudying the following specification in conjunction with the drawings inwhich:

FIG. 1 is a side elevational view of one form of the novel jack or hoistduring hoisting operation, and showing the eccentric and handle beingshifted in an upward movement just before moving downwardly to lift thehoist mechanism;

FIG. 2 is a fragmentary, side elevational view of the apparatus in FIG.1 after the eccentric and handle is in the upper-most position and thehandle is being lowered to raise the chain hoist mechanism;

FIG. 3 is a front elevational view of the apparatus taken in thedirection of Ill as indicated by the arrow in FIG. 2;

FIG. 4 is a fragmentary, side elevational view of the hoist apparatusduring the lowering operation, showing the link by link release of thechain;

FIG. 5 is a top sectional view taken on plane VV of the apparatus asillustrated in FIG. 4;

FIG. 6 is a fragmentary, elevational view of the end of the hoistingchain showing a slightly modified operation thereof;

FIG. 7 is a fragmentary, perspective view of the end of the chain hoistshowing a still different modified operation;

FIG. 8 is a fragmentary, perspective view of a modified form of thejack;

cation of the handle and ececntric.

Patented ec. l, 1964 "ice FIG. 9 is an exploded perspective view of themodified jack;

FIG. 10 is a fragmentary side elevational view of the modified jack;

FIG. 11 is a fragmentary side elevational view of the modified apparatuswith the chain being disengaged from chain catch hook; and

PEG. 12 is an enlarged fragmentary view of the chain link cam and achain link.

Basically, the inventive hoist mechanism comprises a support, a sprocketmeans rotatably mounted on the support, a hoisting roller chain aroundthe sprocket, and a handle-operated eccentric mounted adjacent thesprocket and chain, and adapted to be shifted into engagement with thechain between adjacent rollers to shift the chain around the sprocket alimited amount. The eccentric is pivotally mounted on a bracket, whichis in turn pivotally mounted to the upper end of the vertical support orstand. The eccentric includes a lobe movable into engagement betweenadjacent rollers on the sprocket. Further shifting of the handle shiftsthe chain and sprocket a predetermined amount. Catch means on the standholds the chain in its shifted position with each recipro- Theengagement force of the eccentric on the chain roller is limited by aroller element between the eccentric and its mounting bracket, causing abinding action after. the engagement between the eccentric and rollerchain occurs. Before this binding occurs, the handle and eccentric movewith respect to the bracket. After the binding the handle and bracketmove as a unit.

The hoist apparatus also includes a unique lowering or reverse actionrelease mechanism including a lifting pin means. This lifting pin isactuated by the actuation means on the handle during upward movement ofthe handle. The pin shifts the individual rollers around the chaincatching hook to enable a link by link lowering. The actuating means onthe handle is preferably a magnet which shifts the releasing pin means apredetermined amount to release one link of the chain, and then breakloose from the releasing pin means to allow the next roller of the chainto catch on the hook.

Referring now to the drawings, in the form of the invention illustratedin FIG. 1, the novel hoist apparatus ill includes a support means 12, ahoisting chain means '14, and an eccentric mechanism 16.

The support or stand 12 preferably includes a cylindrical sleeve 18which interfits telescopically with a cylindrical element 29 projectingupwardly from base 22. The upper end of the cylindrical stand ismachined away to provide a slot and a pair of spaced ears 26 and 28illustrated in FIG. 3. Between these ears extends a central pin3ll uponwhich sprocket 32 is fixedly mounted. The teeth of this sprocket projectbetween the adjacent rollers 49 of roller chain 14. The rollers areinterconnected by side links in a conventional manner.

On the front end of the roller chain 14 is provided a hook 432 forhoisting purposes. This hook may interfit with an inverted U shapedbracket 46 welded or otherwise suitably affixed to the lifting support48. The lifting support is integral with a cylindrical guide sleeve Silwhich surrounds the stand 18 and moves vertically up and down on it.Upon the upper surface of this support 48, an automobile bumper 54 maybe placed for hoisting purposes. To alleviate frictional contact between cylindrical sleeve 5 3 and stand 18, a pair of diagonally locatedrollers 56 and 58 are provided.

The opposite end of the chain may pass through a suitable opening 60(FIG, 3) into the cylindrical stand 18 for proper storage of any chainslack as the chain is moved back and forth around the sprocket 32.

Movement of the chain and sprocket is effected with l in FIG. 1.

the eccentric mechanism 16. This eccentric includes a lobe 7i beneaththe pivotal pin 72 where the eccentric is pivotally mounted on thevertically extending bracket 74. This bracket includes two downwardlyextending legs 76 and 78 pivotally mounted on pin 3b,.and includesrollers 46, or out of engagementterewith to allow movement of the handleover the rollers as illustrated The pressure of the lobe '76 on therollers of the chain is limited by the binding action which occursbetween the roller element or ball as inserted between the portion ofeccentric 16 opposite lobe 7t), and the top surface 8t) of bracket '74.Bracket 74 pivots independently of the sprocket 32. Roller member 96 isretm'ned in the housing by downwardly depending front and rear flanges199 and 1&2 on bracket 74. tang 106 of theeccentric.

Thehoisting chain 14 is held in any position by hook H98 which isintegral with stand 13, and projects slightly downwardly asillustratedin FlGS. 1 and 2. Even with the Weight of an automobile (seebumper 54) on support 43, the chain will not allow the sprocket 32 torotate counterclockwiseuntil the chain rollers are released [from thiscatch hook 1'38. 7

During the hoisting operation of the apparatus, handle 84 is rotateddownwardly. It first moves with respect to bracket '74 to cause anengagement between lobe 7d and a pair of adjacent rollers 40 asillustrated in FlG. 2. The binding force of this engagement is limitedby the ball 96 which binds between the upper surface of the eccentricand the top surface 8t) of bracket 7 4 illustrated in FIG. 2 when thehandle is rotated further. Additional downward rotation of the handle 84in the direction of the arrow illustrated in FIG. 2 then causes thebracket 7 4 to also rotate about its pivotal shaft 30 to thereby rotatebracket '74. After it rotates a srnall arnount the eccentric abutsflange 162 and causes the entire bracket to pivot upwardly andcounterclockwise as well as the handle and eccentric. Thereby, thehandle can be pivoted and the bracket can be pivoted counterclockwiseinto its original position illustrated in FIG. 2 to enable anotherdownward movement of the eccentric apparatus. The uppermost position ofthe handle and bracket can be determined by a stop 81 on the bracket(FIG. 1) which abuts the car 78 of the stand 18. The handle isrepeatedly reciprocated until the object is hoisted the desired amountby travel of support 48 up stand 18.

Reverse movement of the apparatus to lower the hoist is accomplished asthe result of two specific actions. First, the individual rollers 49 ofthe chain must be released one at a time from beneath the retainingcatch means or book 1%. Also, movement of the chain in reverse directionmust be manually controlled by eccentric 16 and handle $4 to prevent ajumping action under the weight of the vehicle. I

The first action, i.e. the release of the individual rollers rorn aroundhook 168, is achieved through a special lifting or hoisting pin 134(FIG. 5) which is adapted to It rests in a recess adjacent extendbetween the rollers 49 to enable lifting of each roller one 'at a timearound the book. This pin 114 includes a portion extending throughopening 116 in cylinder 118 (portion 12b) to serve as a guide, aretracting means, and an extension limit means, A tension spring 122 issecured between the inner end of this portion 12b and a screw 124extending across the cylinder 113 to retract the pin. A washer 132retained on portion 12%? by a pin or cotter key 134 limits the extensionof the pin. Pin 1114 also includes a loop-shaped projection 139 whichenable activation of the pin hoist by actuation means 133 on handle 84;.The releasing pin 114 and its extension 132% are extendible to theposition illustrated in FIG. 4 against the bias of spring 122 untilwasher 3132 abuts the inner surface of the cylinder 113.

The actuation means 133 is' preferably a magnet mounted to a handle by asuitable bracket 140 and bolts 142. During the normal hoistingoperation, a keeper 15b is placed across the poles the magnet 138 asillustrated in PEG. 1. Thus, the magnet normally does not actuate thepin releasing means during the upward move ment of the handle 84. Whenit is desired to lower the hoisting mechanism, i.e., cause the chain andsprocket to move in a counterclockwise direction 'as illustrated in FIG.4-, the keeper i5 9 isremovcd from magnet 3138. Then, as handle 84 islowered, the magnet comes in contact with extension 13% of the pinrelease. As the handle is raised again (as illustrated in FIG. 4), themagnet pulls the pin release upwardly and outwardly until washer 132contacts the inner wall of the cylinder 18. As the pin lidis raisedupwardly and outwardly, it lifts a roller lit of the chain aroundhookass to allow that roller to be released for counterclockwise movement ofthe chain. As soon as the magnet has reached the position illustrated inFIG. 4, and the washer 132 abuts the cylinder '18, rfurther movement ofthe handle causes release of the magnet from the extension 13% therebycausing the spring 122 to retract the releasing pinil l. This initialreleasing action occurs. with the ball as at the front of bracket 743 asillustrated in PEG. 4. At the time the magnet releases portion 13%,however, the ball as rolls against ear or tang (see arrow FIG. 4) Ittld.Lobe 7th is engaged'between two adjacent rollers 4th to allow theoperator to manually control the rate at which the chain and thesprocket move counterclockwise to lower the vehicle. 011 the nextdownward stroke of the handle, the operator prevents the binding actionbetween the eccentric 16, ball '96 and upper surface 8%) of the bracket7 to thus prevent the lobe 70 of the cam from engaging between therollers. This done by keeping the handle in its most counterclockwiseposition with respect to the bracket '74 while rotating the handle andbracket clockwise. Gn the downward movement of the handle, therefore, nohoistlog occurs. Magnet 13% then comes in contact with extension 13%again to repeat the lowering step, a link at a time. 1

Gperation of the apparatus as explained with respect to the particularstructure above is thus obvious from this prior description. Briefly,when an automobile illustrated by bumper 5 i is'to be hoisted, itisplaced above support 48. Keeper 15b is placed on magnet E38. Handle asis reciprocated vertically, i.e. in alternate clockwise andcounterclockwise directions to rotate sprocket 32 clockwise. During thehoisting operation, the handle is first deliberately rotated clockwi ewith respect to the bracket 74 to engage the lobe 78 with the rollers4t) and binds the ball 96 between the eccentric and the bracket. Thisengagement is released in the upward reverse direction. Alternatively,when lowering the hoist, i.e. causing the sprocket and chain to movecounterclockwise, the lobe 7 7b is purposely prevented from engagingtherollers 40 on the downward movement, i.e. the handle and eccentric i areretained in their counterclockwise position with respect to the bracket745 011 the downward movement, and on the upward movement, lobe 7th ispurposely engaged $3 with the rollers. Since the weight of the vehicletending to move the chain in a counterclockwise direction will tend toforce the handle upwardly and the operators hand will be pushingdownwardly on the handle, the handle eccentric will be in the clockwisemost position with respect to the bracket to control the downwardmovement of the chant.

Instead of the apparatus being used in the form illustrated in FIG. 1with the support 48 directly onto the hook 42, the hook 42 may be useddirectly on a bumper 54 as illustrated in FIG. 6. Alternatively, theU-shaped inverted bar 46 may be provided with a roller 18% fittingbetween the side links of the chain 14 as illustrated in FIG. 7. In thisform of the invention, not only will the bumper 54 rest on the support48, but also the chain will pass around the roller 130 and hook 42 willengage the top of bumper 54 to hold it in a secure manner. Thus, raisingof the chain illustrated in P16. 7 will cause movement of the chainalong roller 18% to give a smooth controlled hoisting or lowering of thevehicle. Obviously, various other forms of securing the chain hoist tothe particular article to be hoisted or lowered may be utilized.

Modified A ppamius Referring to FIGS. 8 through 12, a modified andpreferred form of the apparatus using a mechanical cam to release thechain, instead of the magnetic releasing means, is illustrated. Thenovel modified jack 2% includes a suitable base, an upright support 2&9,a pivotal handle bracket 2%, and a camming handle 2% similar to those inthe previously illustrated form.

The upright 262 includes a pair of oppositely positioned vertical slots2&8, in which the chain sprocket Zltl fits to be rotatably mounted ontransverse pin 212. The pin is rotatably supported on upright post 2% ina pair of opposite openings 214, 90 removed from slots 2498. The rollerchain 22% includes suitable bumper hook means (not shown in FIG. 8 butsimilar to the previous type shown) attached to end 22th of the chain.The other end of the chain is slack, and may be positioned within thehollowed post 2&2 through a suitable orifice 224. The roller chainpasses over the top of sprocket 218 as previously.

Bracket 2% has a pair of spaced openings 23th and 23b in the lower endsof its legs to be pivotally mounted upon pin 2&2. extending through thetop of the post. The bracket also includes a pair of openings 234 nearits upper end to receive cylindrical pin 2%, also inserted throughopening 238 in the eccentric head 245 on the end of handle 2%. Theopening 233 is mounted oif the center line of eccentric 249, to causethe lower eccentric surface 24% to move into engagement between a pairof links of the roller, chain, or out of engagement therewith when thehandle is pivoted upon pin 236.

The head normally fits between the legs of the generally invertedU-shaped support bracket 2&4. Thus, the handle may be pivoted withrespect to the bracket, and the bracket may be pivoted with respect tothe post, as necessary. Pivoting of the handle moves the eccentric intoand out of engagement with the roller chain, while pivoting of thebracket enables a bite to be obtained on the chain when the handle isdepressed for engagement of the eccentric with the roller chain. The topof the eccentric 246 includes a recess 25% within which a ball 252 fitsin order to lock the handle with respect to the bracket 2% as describedwith respect to the previous modification.

Protruding from the surface of cylindrical pin 212 is an engagementtooth 26% which fits within slot 262 out into the periphery of the postopening 214. The slot is provided with an arcuate width somewhatgreater. than the width of element 269, to allow a slight amount of playbetween the cylindrical pin and the slot. Also, the opening 23% on oneside of bracket 204 includes a wide arcuate slot 2232 cut into itsperiphery to receive a control stop 270. The control stop lever 27% hasa cylindrical shank 272 which fits within a special opening 274 inconnecting pin 212 to allow rotation of the control stop on a 90 angleusing its handle 276. The arcuate width of slot 232 is substantiallygreater than the width of stop 27% to allow bracket movement withrespect to the special stop 27%, for taking repeated bites on the jackusing handle 2%.

it will be observed that surface 23% of stop 276 is displaced from therotational anchoring shank 272 a greater distance than surface 232 whichis removed 90 from surface 28%. Consequently, by rotating stop 270 usinghandle 276, either surface Ziih or surface 282 may be alternativelyplaced to abut the end surface 2% of slot 232 in bracket 2%, therebylimiting the arcuate bracket movement to two different values. Theoperation will be more specifically described hereinafter.

Positioned beneath slot 2% is a chain hook catch 2% as previously, toanchor the chain and prevent it from moving when a load is appliedthereto.

Mounted to post 202 by pivotal elements 3% is a special U-shaped cam 3&2having its legs straddling the post for pivotal connection thereto, andhaving a special toe with a curved concave frontal surface especiallyadapted to interfit with one of the chain rollers 3% as shown in FIG.12. When rotational camming element 3232 is pivoted to its down positionon orientation (as illustrated in FIG. 9), it is out of engagement withthe roller chain. When, however, the pivotal cam is rotated upwardly toa position toward horizontal (i.e. clockwise in the form of theinvention illustrated in FIG. 9), the concave surface on toe 394 engagesone of the rollers (as illustrated in FIG. 12) to push the roller chainoutwardly away from the post 262 and around hook catch 298 as the chainlifts the cam, to allow the chain to move in a reverse direction forlowering a load on the end 220' of the chain. The cam 25% includes ancar 310 projecting therefrom for engagement with a stop bar 312protruding from the post 262. Engagement of this car 31% with the stopbar 31.2 limits the upward movement of the cam element 392 and thus oftoe 304 to a position below the horizontal plane. At this position theroiler chain is moved past the catch 298 sufiiciently to allow oneroller link to move past the catch. At this time, the mechanism allowsthe next adjacent roller link to become engaged with the catch, as theweight of the load upon the chain automatically pulls the chain out ofengagement with the concave toe 3%, allowing the camming element 362 todrop down to its downwardly biased position by its Weight.

When a load is to be raised on the end 22! of the roller chain by thejack assembly, as illustrated for example by the arrow in FIG. 8, thehandle 2% is first rotated clockwise (FIG. 8) with respect to bracket204 to disengage the eccentric surface 246' from the roller chain. Thehandle is then raised further to rotate bracket Ztld with respect topost 2% and around pin 214 to enable a bite to be obtained on the chain.The handle is then lowered in the bracket to cause the eccentric surface240' to engage between two of the rollers of roller chain 220.Depression of the handle from the position illustrated in solid in FIG.8 to the handle axis shown by the phantom line 2% in FIG. 8 forces theroller chain around sprocket 210 with rotation of the sprocket on pin212. This causes an adjacent roller link to move around the slightlydownwardly curved ear catch 2% and catch thereunder. This hoists theitem the length of one chain link.

When something is to be thus hoisted, control stop lever 27% is pivotedon its shank 212 so that handle 276 protrudes outwardly away from thejack assembly at approximately as shown in FIG. 8. At this position, thestop surface 2% (FIG. 9) is in a position to abut surface 2% of slot 232of bracket 2% (FIG. 9).

It will be seen that tooth 260 positively engaging slot 262 in post N2prevents surface 290 in slot 232 of the V viewed in FIG. ll).

. bracket from rotating stop 279 and pin 212 when force is appliedtherebetween, as it would if this positive engagement of tooth 26%) withits respective slot 262 were not present. 7

The phantom line illustrated in FIG. 8 at 2% is the lowermost positionof handlezlld when hoisting something, since contact of surface 23% withsurface 2% limits the downward handle movement. At this position, thelower edge of bracket 2% is not low enough to form'an operative abuttingengagement with car 318 on cam 3&2. Thus, to take another bite on thejack and hoist the mechanism one further link, the handle is liftedagain to move eccentric surface 246' out of engagement with the rollerchain and then rotate bracket 264 on pin 2E2 with respect to post 202.The handle islowered again. This process is repeated until the articleis at the desired height. I

To lower the article on the jack in a closely controlled manner, firstcontrol stop 27% is rotated 90 so that book 276 lies alongside bracket204 (as illustrated in FlGS. 9, 10 and 11). In this position, thecontacting surface of the stop is 282 to abut surface 290 of slot 232atthe lowermost position of the handle. It will be noted that sincesurface 282 is substantially closer to the pivotal axis of the shank ofstop 2'70, bracket 2% maybe rotated counterclockwise further than itcould when hoisting something. This puts the haudleand bracket in alower position. Y

To lower'an article, therefore, the handle is first placed in theposition illustrated in FIGURE 10 to put bracket Ell-'2 in the positionillustrated in FIGURE it), usually almost vertical. The'handle is thenlowered to rotate the bracket and cause its lowered edge to contact ear3E8 of special, rotational, U-shaped chain shifting earn 302 (FIG. 11).

face 304 on the toe of the cam is in operative engagement with one ofthe rollers 306 on the chain'as shown in FIG. 12. Lifting of the handleto move the eccentric 246 out of engagement with the chain, therebyallows the force on the chain to move the chain and cam slightlyupwardly. The upward movement of this portion of the 1 chain (see'arrowin PIG..11) causes the roller to carry out of'engagemcnt with itsholding catch 29% until one of the roller links passes by the hook.Further, rotation of thechain and cam 36:2 causes engagement of car 31%with stop 312 so that the weight of the load on the chain forces thechain to disengage from the slightly concave surface to toe 334. Thisenabiesthe cam 392 to drop down against the post, and allow the chain tomove inwardly again so that'the next roller link engages behind thecatch After the chain has moved past the hook one link, this process isrepeated again and again by merely lowering the handle again to rotatethe cam 382 outwardly into engagement with the next adjacent link, etc.

It has been found that the novel jack works completely dependably andeffectively for hoisting automobiles, and buildings, as examples. It hasremarkable leverage to enable its use safely and efiectively whereverdesired.

Various additional modifications of the apparatus, withv in theinventive principles taught may be apparent to those in the art uponstudying the foregoing forms. These At this position the concave surofsaid sprocket and including hoisting means on one end; a bracketextending'above said sprocket and adapted to oscillate on said support;an eccentric rotatably mounted on said bracket adjacent said sprocketand chain; said eccentric having a lobe movable into engagement betweenadjacent rollers of said chain on said sprocket; handle "leansprotruding from said eccentric enabling movement of said lobe intoengagement Withsaid chain with further rotation of said eccentriccausing shifting of said chain around said sprocket; chain catch meanson said support to hold said chain in its shifted position; a rollingclement between said bracket and a portion of said eccentric oppositesaid lobe; said rolling element being movable to a first position tobind between said bracket and eccentric when said eccentric is shiftedinto engagement with said chain to thereby cause said eccentric, handle,and bracket to shift together, and movable to a second position to befree from binding when said eccentric and chain are out of engagement,to allow said handle and eccentric to shift with respect to saidbracket.

2. A hoist mechanism comprising: a support; a sprocket rotatably mountedon said support; a hoisting roller chain around said sprocket; aneccentric mounted adjacent said sprocket and chain and adapted to beshifted into engagement with 'said chain between adjacent rollersthereof to shift-said chain around said sprocket; a handle on saideccentric; catch means on said support adapted to secure said chain whenshifted; and release means mounted on said support, and operablyassociated with said handle and 'shiftable therewith to release asection of said chain from said catch means with each oscillation ofsaid handle I to allow reverse movement of said chain on said sprocket.

3. The mechanism in claim 2 wherein said catch means is a hook, and saidrelease means is a biased pin adapted to move under rollers of saidchain when shifted, to shift them ofi said hook.

4. The apparatus in claim 3 wherein said pin is shiftably actuated byactuating means on said handle.

5. The apparatus in claim 4 wherein said actuating means is a magnet onsaid handle in operative relation to I said pin to actuate said pin andrelease rollers of said chain one by one around said hook.

6 A hoist mechanism comprising: a support; sprocket means on saidsupport; a roller chain around said sprocket means; manual chainshifting means including a handle; chain catch means on said support inoperative engaging relation to said chain; means on said support,shiftable to release said chain from said catch means; and a magnet onsaid handle positioned to shift and actuate said release means.

7. A hoist mechanism comprising: a support; 'a sprocket rotatablymounted on said support; a hoisting roller chain around said sprocket;an eccentric mounted adjacent said sprocket and chain, positionedadjacent said chain, and movable toward and away therefrom to be shiftedinto engagement with said chain between adjacent rollers therei of toshift said chain around said sprocket; a handle on said eccentric toshift it; catch means on said support adjacent said chain to engage andsecure said chain when the chain is shifted by said eccentric andhandle; and release means adjacent said catch means, operable withmovement of'said eccentric and operably engageable with said chain toshift and release a section of said chain from said catch means witheach oscillation of said handle and eccentric to allow reverse movementof said chain on said sprocket; said release means comprising a camelement pivotally mounted to said support and engaging sai roller chainonly temporarily to shift it out around said catch means and beingconfigurated to be releaseable therefrom after shifting said chain outaround said catch means, to return to its initial position.

8. A vehicle jack comprising: a vertical support; a

sprocket rotatably. mounted adjacent the top of said support; a rollerhoisting chain adapted to pass over the top of said sprocket; a bracketextending above said sprocket and adapted to oscillate on said support;an eccentric rotatably mounted on said bracket adjacent said sprocketand chain; said eccentric having a lobe movable into engagement betweenadjacent rollers of said chain on said sprocket; handle means protrudingfrom said eccentric enabling movement into engagement with said chain,and rotation of said eccentric causing shifting of said chain aroundsaid sprocket; and chain catch means on said support to hold said chainin its shifted position; a chain release cam element pivotally mountedto said support and having a chain engaging surface; said cam elementbeing engageable by said bracket to rotate the cam element intooperative engagement with said chain to release the chain temporarilyfrom said catch means.

9. The jack in claim 8 wherein a variable control stop is positionedbetween said bracket and support and mov- 1% able between first andsecond positions therebetween to cause binding therebetween and hoistingaction in said first position of said stop, and to release the bindingcondition therebetween and cause lowering action in said secondposition.

FOREIGN PATENTS 17,616 11/90 Great Britain.

WILLIAM FELDMAN, Primary Examiner.

MILTON MEHR, Examiner.

2. A HOIST MECHANISM COMPRISING: A SUPPORT; A SPROCKET ROTATABLY MOUNTEDON SAID SUPPORT; A HOISTING ROLLER CHAIN AROUND SAID SPROCKET; ANECCENTRIC MOUNTED ADJACENT SAID SPROCKET AND CHAIN AND ADAPTED TO BESHIFTED INTO ENGAGEMENT WITH SAID CHAIN BETWEEN ADJACENT ROLLERS THEREOFTO SHIFT SAID CHAIN AROUND SAID SPROCKET; A HANDLE ON SAID ECCENTRIC;CATCH MEANS ON SAID SUPPORT ADAPTED TO SECURE SAID CHAIN WHEN SHIFTED;AND RELEASE MEANS MOUNTED ON SAID SUPPORT, AND OPERABLY ASSOCIATED WITHSAID HANDLE AND SHIFTABLE THEREWITH TO RELEASE A SECTION OF SAID CHAINFROM SAID CATCH MEANS WITH EACH OSCILLATION OF SAID HANDLE TO ALLOWREVERSE MOVEMENT OF CHAIN ON SAID SPROCKET.